Commutator brush and holder for dynamos and the like.



PATENTED JAN. 8, 1907.

J. A. MISLAND. GOMMUTATOR BRUSH AND HOLDER FOR DYNAMOS AND THE LIKE.

APPLICATION FILED DEC. 7. 1905.

JOSEPH A. MISLAND,

OF NEW YORK, N. Y.

COMMUTATOR BRUSH AND HOLDER FOR DYNAIVIOS AND THE LIKE.

To all whom it may concern:

Be it known that I, JOSEPH A. citizen of the United States, residing inthe borough of Brooklyn, in the county of Kings, in the city and Stateof New York, have invented certain new and useful ImprovementsinCommutator Brushes and Holders for Dynamos and the Like, of which thefollowing is a specification.

This invention relates to the contact- I brushes used on the commutatorsof dynamos and electric motors, and to the holders for such brushes; andthe object is to provide for the proper contact of the brushes at alltimes, especially when the motor or dynamo is reversed, so that fullcontact may be had at all times and under all conditions and sparking orthe formation of corroding arcs at the commutator is avoided.

It is a known fact that in the use of solid brushes bearing radially ona cylindrical commutator which is liable to be rotated in eitherdirection the frictional peripheral contact of the periphery of thecommutator running in one direction tends to and does deflect or swingthe brush so as to wear the contact end of the brush off most at theback or rear corner and that when the commutator is reversed the brushis swung the other way and a bad contact s the result. The worst effectof this is the formation of arcs, which eat or burn away both thecommutator and brush, and thus increase the difl iculty. This is due tothe fact that the brush must be fed up to the commutator radially to thelatter as the brush wears away, and the necessity for this freedom ofmovement in feeding involves always some lateral play of the brushwhereby in the constructions now in use in the reversal of the directionof rotation the drag of the commutator on the brush shifts the latterout of its proper radial position first in one direction and then in theother.

The present invention provides a means for holding the brush up to theperiphery of the commutator squarely and radially at all times and forfeeding it forward as it wears away. I In the accompanying drawings,which illustrate an embodiment of the invention, Figure 1 is a sideelevation of the brush and its holder. Fig. 2 is a rear elevation asseen from the right in F g. 1. Fig. 3 is a transverse section at line 00Fig. 4 is a I in Fig. 2. vertical section at line m in Fig. 2. Fig. 5 1SSpecification of Letters Patent. Application filed December 7,

MIsLAND, a I brush detached.

Patented Jan. 8, 1907. 1905. Serial No. 290,738.

a detached view of the socket-plate of the In the views, O designates apart of any cyl ndrical commutator of a dynamo or electric motor, and isa part of the bracket on the frame to which the brush-holder is secured.These features are well known in the art and will need neitherillustration nor elaborate description.

The holder 1 may be cast metal adapted to receive one or more brushes 2of the usual material and of oblong block-like shape. The brush hasfixed to it and recessed in its face a metal socket-piece 3. (Seendetached in Fig. 5.)

Mounted in the frame are rollers 4, against which the upright brush ispressed by a spring-plunger 5. This plunger has a rounded end 6,whichengages the socket in the socket-piece 3, and it has near its outerend a loose bearing at 7 in a frame 8 on and forming substantially anintegral part of the holder 1. The plunger 5 is disposed obliquely tothe face of the brush, and the plunger-spring 9 is embraced between ashoulder 10 on the plunger in the frame 8, as clearly shown in Fig. 4.On the outer end of the plunger is a nut 11 and limiting-washer or stop12.

It will be noted that the brush is always radial to the commutator, asindicated b the dotted line 2 in Fig. 1, and that as it wears away thepressure of the plunger obliquely on it keeps it pressed up closely tothe periphery of the commutator. At the same time the spring-plungerprevents the brush from swinging or being dragged out of its radialposition when acted upon by the frictional contact of its end with theperiphery of the rotating commutator, no matter in which direction thelatter may be rotating.

The bearing 7 is of such a form that it permits the plunger to adaptitself to the slight change in obliquity it must assume as the brushgradually wears away. Preferably there will be two or more brushes inthe ame rather than one wide brush, and the brush will be embraced atits edges by flanges on the holder to prevent edgewise movement.

The rollers 4, disposed back of the brush, so as to take the pressurefrom the springplunger, is very important, as the bearing of the brushon a flat stationary surface, as in the ordinary construction, wouldproduce so ICC much friction as to render the feeding of the brushirregular and uncertain. The rollers should be so placed that thebearing-point of the plunger 5 on the brush will be at a point betweenthe outer and inner rollers, as clearly shown in Fig. 4c. Thisdistributes the pressure between the rollers and prevents chattering.

The socket-piece 3 may be considered in a structural sense a part of thebrush. As the brush is usually made from some relatively weak and softnon-metallic material and it is necessary for the oblique plunger tofind a bearing thereon, the socket-piece shown is provided. This devicemay be considered as a bearing-piece or piece to take the wear andprovide a suitable step to receive the end of the plunger. It is in thissense that the word socket is used herein.

Having thus described my invention, I claim 1. A commutator-brushprovided with a socket 3, set into the brush and provided with aconcave' recess, in combination with a holder for the brush providedwith rollerbearings for the latter, and with a springplunger having asocket on the brush, said plunger be1ng disposed obliquely to the faceof the brush and convex end engaging the l having a loose bearing at 7,to enable it to vary its obliquity.

2. A commutator-brush provided with a socket set into the brush andprovided with a concave recess, in combination with a holder for thebrush provided with a spring-plunger having a convex end engaging saidsocket in the brush, said plunger being disposed obliquely to the faceof the brush and having a loose bearing to enable it to vary itsobliquity.

3. The combination, with a commutatorbrush, provided with a socket-piece3, set in its face, of a holder 1, having in it a guideway for thebrush, rollers on which the back of the brush bears, a frame 8, and aspring-plunger mounted loosely at 7, in said frame with its rounded endengaging the socket on the brush, said plunger having its axis obliqueto the axis and the direction of movement of the brush.

In witness whereof I have hereunto signed my name, this 5th day ofDecember, 1905, in the presence of two subscribing witnesses.

JOSEPH A. MISLAND.

Witnesses HENRY CONNETT, WILLIAM J. FIRTH.

